Top Tips to find a good fan fiction:
1. Good summary: no grammatical errors, no "I can't really write a summary", no "I promise the story is better than it seems" and the summary gives you a basic idea of what the story is about without giving away the plot.
2. Review count: 10 reviews per chapter can be considered average, depending what fiction is written. A Harry Potter fiction is going to be read more than an Eragon fiction and will probably get more reviews.
3. Chapter length: a multi-chaptered fiction should be around 3,000 words per chapter. Because this shows the authors have planned ahead. 500 word per chapter indicates that the authors is just writing the fiction as the idea struck him/her without planning on what will happen in the next chapter.
4. Update intervals: a story that has very long update intervals means that the author is very busy and probably do not write as well as they could have if given more free time. Some authors though defy this by continuously posting a very well-written chapter or one shots.
5. A good first chapter: if a fiction's summary and review count manages to entice you into reading it, you will be able to tell whether it is a good fiction or bad by reading the first chapter of the fiction. A good fiction has little grammatical errors, little spelling errors, and the readers can interpret what the author was trying to convey from his written words.
Common spelling and grammatical errors.
1. Definitely vs Defiantly: Definitely means: without question and beyond doubt. Whereas Defiantly means: in a rebellious manner.
2. You're vs Your: You're is the short form of You Are. Whereas Your is the possessive form of the word you. Example:You're a fan fiction author. Is this your fan fiction?